Cartridge belt link



p 1949, J. J., MURPHY 2,480,950

CARTRIDGE BELT LINK v Filed July 14, 1945 2 Sheets-Sheet 1 S p 1949. J;J. MURPHY CARTRIDGE BELT LINK v 2 Sheets-Sheet 2 Filed July 14, 1945Patented Sept. 6, 1949 UNITED STATES ATENT OFFICE CARTRIDGE BELT LINKApplication July 14, 1945, Serial No. 605,079

3 Claims.

This invention relates to metallic cartridge belt links, moreparticularly to metallic cartridge belt links which are interlinked andhinged together by the cartridges received in the links to form a beltof ammunition and it is an object of the invention to provide animproved cartridge belt link of the character indicated.

The universal character of the movements of a rapid fire gun duringoperation from both relatively fixed and rapidly moving gun mounts andthe necessity for an ammunition belt havin the required attributes offlexibility in order to satisfactorily operate in the gun are wellrecognized. Likewise, it is known that the limitations of space around agun are such that annnunition belts must be stored in awkard butrelatively accessible places not always convenient to the gun, therebymaking it necessary that the ammunition belt be capable of additionaltwists and turns. A cartridge belt link fulfilling the necessaryrequirements as to flexibility when assembled into an ammunition belt isdescribed and claimed in a co-pending patent application Serial No.469,679 filed December 21, 1942 in the name of Roy S. Sanford andentitled Cartridge belt link, and issued on December 4, 1945 into PatentNo. 2,390,331, which patent is assigned to the same assignee as thepresent invention. The cartridge belt link of the said Sanfordapplication comprises two cartridge-receiving members connected by auniversal joint which permits thecartridgereceiving members to moverelative to each other as the ammunition belt twists and turns duringuse. With universal joints between the links holding the rounds ofammunition and because the rounds are mounted in the links substantiallyat their centers of gravity, the jerks and movements imparted to theammunition belt by the short jerking movements of the gun feedingmechanism and the additional jerking move ments caused by rapidly movingthe gun from one position to another, may give rise to a tendency forthe rounds to flop indiscriminately from one position to another out ofline and to remain out of line. Accordingly, it is a further object ofthe invention to provide an improved cartridge belt link of thecharacter indicated having a restrained swivel or joint by virtue ofwhich the relative movement between the members of the link brings intooperation a force tending to restrain the relative movement.

It is a further object of the invention to provide an improved cartridgebelt link of the character indicated in which a, force is brought intooperation by the relative movement of the link members from a normalposition to return the link members to a normal position relative toeach other after displacement therefrom.

Ammunition belts having a, large number of rounds are heavy andconsequently the feeding mechanism of a gun must exert a strong pull tofeed the ammunition. The ammunition in its pathway to the gun passesaround feed and uide rollers and through guide chutes which necessitatethat the rounds twist and turn to some degree, and it is apparent thatsuch twists and turns must be made with as little resistance as possiblein order not to increase unduly the load on the gun feeding mechanism.Accordingly, it is a further object of the invention to provide animproved cartridge belt link of the character indicated in which theforce restraining the movement of the members of the link relative toeach other is initially small and increases as the amount of therelative movement increases.

The sharp quick jerks of the gun feeding mechanism are imparted to thewhole ammunition belt and consequently accelerate the ammunition beltwith the same short jerking movement. This not only places a heavy shockor acceleration load on the gun feeding mechanism, but it places a heavystrain on the cartridge belt links immediately adjacent the gun whichbear the total force exerted in moving the ammunition belt. Accordingly,it is a further ob-' ject of the invention to provide an improvedcartridge belt link of the character indicated in which there isrelative movement between the link members in the direction of feedingand the relative movement is resiliently restrained so as to provide ashock absorbing effect.

In carrying out the invention in one form, a cartridge belt link isprovided having two cartridge-receiving members which are joined to eachother with a universal joint and have a normal position and a limiteddegree of movement relative to each other. One of thecartridge-receiving members comprises a pair of axially spacedcartridge-receiving elements with an integral bridging member connectingthe elements, the bridging member including a centrally disposedaperture and a pair of spaced guides defining the edges of the aperture.The second cartridge-receiving member comprises a resilient singlecartridge-receiving element having a pair of tongues extending therefromthrough the centrally disposed aperture and terminating in a pair oflaterally projecting lugs which engage the bridging member to connectthe two members of the links. The pair of tongues extend anguand theother end is provided with a tongue 3| fitting thereinto, the endstapering away from the cutout portion and the tongue. While the crosssection of the element 13 may be of any desired shape, it is shown asbeing circular to facilitate the insertion of the cartridges.

The cartridge-receiving member l2 comprises a single split loop orelement substantially circular in form and is somewhat larger indiameter than the diameter of the cartridge received thereby so that theloop may contract during certain of its functions and in order that thecartridge may fit loosely in the loop as shown by the broken line 9 inFig. 4 to permit the links to pivot readily about the cartridges andfacilitate bending around feed and guide rollers. Referring to Figs. 2and 4, the loop I2 is seen to be in the form of a split ring having twoparts 36 and 31' spaced apart by a slot 38 which extends substantiallyaround the loop. The loop I2 is open at one side thereof providing twoends, each terminating in a narrow integrally formed tongue 34. Thetongues 34 extend upwardly from the ends of the loop and terminate inthe lugs 35 which extend laterally from the tongues, the lugs extendingthrough the aperture 23 and serving to connect the element l2 to thebridging member Hi to join the link members together. The tongues 34 aresubstantially rectangular in cross section, thereby providing flatsurfaces facing the curved edges 23 and 24 in the assembled condition,and are bent at an angle to the ends of the loop l2 to extend angularlyoutward from their junction therewith so that the outermost ends of thetongues from which the lugs 35 project are spaced a greater distanceapart than the innermost ends of the tongues which join with the loopl2. At the junction of the tongues with the loop proper there are cutoutportions 39 from which the tapering ends 40 of the loop parts 36 and 31extend to the edges of loop, the cutout portions and the tapering edgesproviding for the desired degree of movement of the link parts relativeto each other. The loop I2 is resilient and in the unassembled conditionit is sprung outwardly as shown by the dotted outline of Fig. 4.

The cartridge-receiving members I! and I2 are separately formed fromflat metal stock by stamping a blank having the desired outline, bendingor otherwise forming the blank into the desired shape followed by heattreating and finishing operations. The member 52 is assembled to themember I I by compressing the loop I2 from the dotted position shown inFig. 4, thereby pressing the tongues 34 and lugs 35 together andinserting the lugs and tongues through the aperture 23. Thereafter theloop is released and through its resilience it expands to the positionshown in Fig. 6 and by the solid outlines of Fig. 4, in which positionthe tongues 34 at their junction with the loop l2 bear against thecurved edges 24 and 25 and the lugs 35 are spaced upwardly from the base16 of the bridging member. In the event that force is exerted tending topull the members I I and I2 apart, the tongues 34 are forced to movetoward each other by virtue of their angular direction and the lugs comeinto contact with the base of the bridging member and effectivelyprevent the links from coming apart. An assembled ammunition beltconsists of a number of links with their loops l2 placed between theelements 13 and I4 of adjacent links and cartridges inserted into thethree loops in a row.

During use, the ammunition belts make numerous twists and turns therebyplacing stresses in the links and causing the various parts of the linkto move relative to each other. It is highly desirable that there be aslittle resistance as possible to the movement of the link parts relativeto each other during the twists and turns of the belt while it is beingused, so that there will be no more than the minimum load placed on thefeed mechanism arising out of the necessity of deforming the links toobtain the twists and turns of the belt. It is equally desirable thatthere be some resistance *to the movement of the link parts relative toeach other to prevent the cartridges from indiscriminately flopping fromone position to another due to random causes and that there be somemeans :to bring the cartridges back into a straight line afterdisplacement therefrom.

' Referring to Fig. 5, the bridging member 15 'of the member II and thelugs 35 of the loop member l2 are shown in two relative positions, thenormal position being shown by the solid outline of the lugs and thedotted outline of the lugs '35 indicating the position of the parts whenthe members H and [2 are turned relative to each Lother so that the axesof the two members are turned in planes which are perpendicular to theplane containing the axes of the two members before turning. Since theedges 24 and 25 are curved and the tongues 34 are fiat, in the normalposition of the link members one of the tongues contacts the curved edgeor guide 24 at two points M and 42, and the other of the tonguescontacts the curved edge 25 at two points 43 and 44, the tongues beingbiased into the two-point contact by the spring action or resiliency ofthe loop I2. When the two members of the link are turned to the positionindicated by dotted lines, it is seen that each of the tongues has movedto a position where one tongue contacts the edge 24 at only one point42a and the other tongue contacts the edge 25 at only one point 4311,the points 42 and '43 having moved along the curved edges to the points4211 and 43a, with the result that the tongues have moved closer to eachother, as shown, and thereby have increased the spring force exerted bythe loop l2 tending to return :the tongues to the normal position.

The movement of the tongues toward each other is made up of twocomponents. The first of these arises out of the fact that the radiusfrom the center of the aperture 23 to the point 42 or 43 is less thanthe radius of the curved edges 24 and 25 as previously pointed out.Therefore the curved edges 24 and 25 lie inside of a circle, indicatedby the arcs 45, having the center of the aperture as a center and thedistance to the point 42 or 43 as a radius. Consequently, when thetongues are rotated the edges of the tongues following the curved edges24 and 25 are forced inwardly. After the edges of the tongues have movedto the points 42a and 43a, the friction of the tongue edges against thecurved edges causes the tongues to become relatively stationary and thetongues pivot about the points 420, and 43a as centers, thereby alsocausing the tongues to move closer together and giving the secondcomponent of movement. The amount of movement of the tongues is limited'by the fact that one edge of each tongue comes into contact with thebosses or projections 25.

Since the tongues are resiliently biased in the outward direction by thespring action of the loop l2 and the tongues bear against the curvededges or guides at only one point When in the rotated position, it isevident that there is a component of force creating a torque which tends'to rotate thetongues and return them to the-normal position, :and ifthe force resisting the return is .not-toogreat, the tongues will com-:pletely return to the 'normal position. Further- :more, the :edges '24and 25 being curved, the re- :siliencyzof theloop [-2 causes the tonguesto seek their .outermost position which occurs when the tongues: aresymmetrically arranged in the aperture 2-3 between the ends of theaperture with eachtongue having a two-point contact Withlthecorrespondingcurved edge, and thus the member 42 is also restrainedfrom movement in directions along its axes.

Referring :to Figs. 6, '7 and 8 illustrating the relationship of-theelements of the link when the two cartridge-receiving members are turnedrelative :to each-other so that the axes of the :two members are turnedin a plane containingrboth of the axes, Fig. 6 shows the mem- .bersinrthe :normal :position and Figs. 7 and 8 .-show the members in theturned position. In this type :of .turning, if .a series of cartridges.and the assembled links were lying on a flat surface, the :baseswof thecartridges or the noses thereof would .be-pointing toward the center of.acircle.

- Referring.:-first to Fig. 6, it is seen that in the :normal position50f the members the base It of the bridging member 15 is in contact withthe .-lo.op-l 2 substantially-at the junction of the tongues 134 and theloop [2, zthe lugs 35 being spaced upwardl-yirom :thebase 1-6. Referringto Fig. 8 (the turned :position), it is seen that the point ofintersection of :one of the tapered ends 46 with the correspondingcutout portion 39 bears 'against the bottom surface of the base 16 at.point 46, and-the opposite edges of the lugs \3-5 bear against .the.top surface of the base l6. In this position the turning movement iscom- ;plete and further turning is impossible. During this turningmovement the member l2 pivots or iulcrums about points A?! which are thepoints where the outside surfaces of the tongues 34 .contact the lower(edge of the curved edges or guides .24 and 25. 'Fig. 7 is an end viewof the structure shown in Fig. 8, showing the turning movement completewith the lower surface of the lugs 35 .in contact with the upper surfaceofzthe bridge 16.

.-It will be apparent that "when the member I2 ;is-,pivotedor turnedabout the pivot points 41, thehfront edge of the tongues remain incontact with-thecurved edges or guides 24 and 25, and hence by virtue ofthe fact that the tongues extend :upwardly and outwardly at an angle,the tongueswill be forced inwardly by an amount depending on the angleat which the tongues zextend from the loop 12. This, as well as theamount of the movement, is seen from comparing Figs. 6 and 7. Since thetongues are ressilientlylbiased outwardly, they tend to resist in-'.ward movement and because of such inward \movement there is a greaterforce tending to lmove the tongues outward, the outward force ha-ving acomponent along the angular tongues which .creates a torque urging thetongues into the -normal;position. That is, rotating the member J2lcauses the base It to climb upon the angular edges :of :the tongues toa position of in- .stability, and :unless some force is exerted to:cause it to remain there, it will return to the Flowermost or stableposition.

Closely allied with the turning movement describedin connection withFigs. 6, 7 and 8 is a mevement-ofsthe members of the link which may betermed 1stretchin g,=.-inthat the members H and I2 moveapart'with theiraxes in the same plane. Considering Figs. 6 and .7, and :assuming thatthere .is no: turning cor twisting but that a downward force :is exertedon .the loop I12 while the bridging member-d5 -iswstationary, thedownward forcewill cause-the :loop 42, and consequently the tongues 34,to move downwardly to a position corresponding to the front edge view.of the tongues in Big. v'7, and consequently the tongues are-movedinwardly toward each other.

By virtue :of the angularly extending tongues, the force tending to move.the-tonguesoutwardly has a component alon -the tongues tending toreturn them .to :theuppermost position shown in Fig. 6 wherethflflOWGP-SllfffiCB of .the bridging member touches the loop A2. Themovement-of the tongues relative to the bridgingmember I5 is thusresiliently .resisted' and permits th ammunition belt .to elongateresiliently under the jerks of the :gun feedin -:mechanism, etc.,thereby preventingshocks to thegun and other equipment. -Inanwactual-operation, of course, there will be complex movements, but thetotal movements ofthe llinktmembers may be resolved into componentswhich are thesimple ones described and the :foregoing-explanations willapply.

While a particular embodiment has been shown, it will be understood, ofcourse, that the invention .:is not limited .thereto since manymodifications may b made, andaritis, therefore, 0011'- templated by theappended claims"tocover any such modifications ascome within the truespirit andscope of :the invention.

Having thus' describedithe invention, what is claimed and ldesired itozbe secured by Letters .Patent is:

1. A cartrige'belt link comprising ;a first cartridge-receiving--member{and a second cartridgereceiving member having. .a normal positionrelative thereto and havinga limited-degree of move-- ment relativethereto, said first cartridge-receiving member comprising apair-ofaxially spaced cartridge-receiving elements, :a bridge member connectingsaid axially :spaced cartridge-receiving elements havin an aperturedisposed-between said elements, theredges biz-said aperture definingspaced curved guides, saidsecondmember comprising aresilient singlecartridge-receiving ele- .ment and :a "pair of tongues extendingvangularly .from said single element through said {aperture :and havinga pair 'of'lugs extending laterally from said tongues -for engaging saidbridge toconnect said first and second members, said tongues beingbiased into contact with said-guides by said single resilient elementand having substantially flat surfaces contactingzsaid curved guideswith a two-point contact, .theradiusof curvature of said guidesbeingigrealter than :the :-radius extending from thecenter ofsaidapert-ure torsaid contact points, wherebyssaid movement efiectsmorement of said tongues :into a single-point contact with said guidesrand-thereby creates .a component of force tending :toreturn saidtongues :to said position of two-point contact.

2. A cartridge-belt link :compris'ing afirstcar- 'tridge-receiving;member "and a second cartridgereceiving member having in. normalposition relative thereto and having :a "limiteddegree of movementrelative to said normal :position, .said :moveme C prisingrotationoffthe axesof said members in planes perpendiculantothe planenorma'llycontaining the .axes zof said :members, said firstcartridge-receivingsmemberzcomprising .a pair. of axially spacedcartridge-ereceiving:.1elements, .ra

bridge member connecting said elements having an aperture disposedbetween said elements'and curved spaced guides defining the edges ofsaid aperture, said curved guides bein concave, toward each other, saidsecond cartridge-receiving element comprising a resilient singlecartridgereceiving element and a pair of tongues extending from saidsingle element through said aperture and terminating in a pair of lugsextending laterally from said tongues for engaging said bridging memberto connect said first and second members, said tongues havingsubstantially flat surfaces and bein biased into two-point contact withsaid curved guides b said resilient single element, said guides having aradius of curvature greater than the radius extending from the center ofthe aperture to the contact points of the tongues with the guides andhaving an arcuate extent greater than the width of said tongues, wherebysaid rotation effects movement of said tongues into a single-pointcontact with said guides and thereby creates a component of force toreturn said tongues to said position of two-point contact.

3. A cartridge belt link comprising a first cartridge-receiving part,and a second cartridgereceiving part, one of said parts includingaperture means having opposed outer curved edges and the other of saidparts including a pair of flat longitudinally disposed tongues extendingtherefrom at least one of which is resiliently formed, each of said pairof tongues terminating in an outwardly projecting lug, said tongueextending through said aperture means whereby said lugs engage said onepart adjacent said curved edges for holding said parts together and theedges of said flat tongues engage said curved ed es for resilientlyrestraining relative twisting movement of said parts.

JOHN J. MURPHY.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 2,302,595 Berry Nov. 17, 19422,390,331 Sanford Dec. 4, 1945 FOREIGN PATENTS Number Country Date355,767 Great Britain 1931

